1. Technical Field
The present invention relates to a measurement apparatus and a program. In particular, the present invention relates to a measurement apparatus and a program for measuring gain error or phase error of a quadrature demodulator or a quadrature modulator.
2. Related Art
The output signal of a quadrature demodulator and a quadrature modulator includes a gain error and a phase error of the quadrature demodulator or the quadrature modulator. Japanese Patent Application Publication No. 2000-316031 discloses a method for calculating the gain error and the phase error in a quadrature-demodulated signal. More specifically, this method involves obtaining parameters that cause a value obtained by summing the square of the error between a measured signal and an ideal signal over a designated section to be a minimum, and calculating the gain error and the phase error based on the obtained parameters.
With the method described above, however, a determinant matrix must be solved, which requires a large amount of computation. Furthermore, when there is a large amount of noise in the measured signal, the error in the calculation result becomes extremely large.